This coming weekend will see another monthly CLE challenge. The hunting grounds will be the 50 kHz swath from 270 - 319.9 kHz, with much of this is being shared by DGPS signals here in North America.

The last time this range was covered was in CLE 212, back in October 2016. Conditions were particularly disturbed back then, as described in my CLE 216 Results blog at the time. Propagation should be much better this time, I hope!For those unfamiliar with this monthly activity, a 'CLE' is a 'Co-ordinated Listening Event', as NDB DXers around the world focus their listening time on one small slice of the NDB spectrum.

A nice challenge in this one is to hear the Pikangikum (ON) NDB, 'YPM', on 274 kHz.Although just a 25-watter, thanks to its large vertical, YPM is well-heard throughout North America. Will you log it as well?Look for 'YPM's upper-sideband CW identifier, repeated every 10.5 seconds, on 274.352 kHz with your receiver in the CW mode.

If you are interested in building a system for the new (U.S.) 630m band, the CLE will give you the chance to test out your MF receiving capabilities and compare against what others in your area might be hearing. You will soon know how well your system is hearing.

When tuning for NDBs, put your receiver in the CW mode and listen for the NDB's CW identifier, repeated every few seconds. Listen for U.S. NDB identifiers approximately 1 kHz higher or lower than the published transmitted frequency since these beacons are modulated with a 1020 Hz tone approximately.For example, 'AA' in Fargo transmits on 365 kHz and its upper sideband CW identifier is tuned at 366.025 kHz while its lower sideband CW ident can be tuned at 363.946 kHz. Its USB tone is actually 1025 Hz while its LSB tone is 1054 Hz.Often, one sideband will be much stronger than the other so if you don't hear the first one, try listening on the other sideband.Canadian NDBs normally have an USB tone only, usually very close to 400 Hz. They also have a long dash (keydown) following the CW identifier.All NDBs heard in North America will be listed in the RNA database (updated daily) while those heard in Europe may be found in the REU database. Beacons heard outside of these regions will be found in the RWW database.Here are the final details from CLE organizer Brian Keyte, G3SIA:

Hello all

Our 229th co-ordinated listening event is this weekend, covering a 50 kHzfrequency range - about three times wider than usual.

We can expect very good propagation, but in part of the frequency rangeit might be quite a challenge to tease out the NDB signals from amongthe DGPS ones.Any first-time CLE logs will be very welcome, as always.

Please log the normal NDBs you can identify that are listed in the range(it includes 270 kHz but not 320 kHz).Please send your CLE log to NDB List, if possible as a plain text emailand not in an attachment, with 'CLE229 FINAL' at the start of its title.Show on EVERY line of your log:

# The Date (e.g. '2018-02-23' or just '23', etc.)# UTC (the day changes at 00:00 UTC).# kHz - the beacon's nominal published frequency if you know it.# The Call Ident.

Those main items can be in any order within themselves, but BEFORE anyother optional details (Location, Distance, etc.) later in the same line.

As always, give details in your log of your own location and the receiver,aerial(s), etc. that you were using.If you send any interim logs, be sure to send a FINAL (complete) one.

You can find anything else to help you, including seeklists for your partof the World, from the CLE page, http://www.ndblist.info/cle.htm

Joachim or I will send the usual 'Any More Logs?' email at about 18:00 UTCon Tuesday so that you can check that your CLE log has been found OK.Do make sure that your log has arrived at the very latest by 09:00 UTCnext Wednesday, 28th February.We are hoping to make all the combined results on that day.

(Reminder: You could use any one remote receiver for your loggings,stating its location and owner - with their permission if required.A remote listener may NOT also use another receiver, whether localor remote, to obtain further loggings for the same CLE).

Final details can be found at the NDB List website, and worldwide results, for every participant, will be posted there a few days after the event. If you are a member of the ndblist Group, results will also be e-mailed and posted there.The very active Yahoo ndblist Group is a great place to learn more about the 'Art of NDB DXing' or to meet other listeners in your region. There is a lot of good information available there and new members are always very welcome. As well, you can follow the results of other CLE participants from night to night as propagation is always an active topic of discussion.You need not be an ndblist member to participate in the CLEs and all reports, no matter how small, are of much value to the organizers. 'First-time' logs are always VERY welcome!

Reports may be sent to the ndblist or e-mailed to either myselfor CLE co-ordinator, Brian Keyte (G3SIA), whose address appears above. Please ... give the CLE a try ... then let us know what NDB's can be heard from your location! Your report can then be added to the worldwide database to help keep it up-to-date.